Updated

The last person to admit having seen a missing Indiana University student alive passed a polygraph test when questioned about his version of events, his attorney said.

Defense attorney James Voyles also said his client, Jason "Jay" Rosenbaum, has been cooperative in providing statements to police regarding the disappearance of 20-year-old Lauren Spierer, Fox 59 reports.

Rosenbaum told investigators that he last saw Spierer walking alone and barefoot to her Bloomington apartment in the early morning hours on June 3.

Spierer, who has not been seen since, had spent the night partying with friends.

"He has provided full statements to the police and passed a polygraph that has also been provided to the authorities,” Voyles said of Rosenbaum.

Voyles' statement came after the New York Post reported Monday that Rosenbaum hasn't been forthcoming in providing information to police and the young woman's parents.

The newspaper, citing family friends of Spierer's, reported that Rosenbaum has refused to speak to the woman's parents and investigators.

Rosenbaum, a 21-year-old student at the university, is considered a "person of interest" in the case -- along with the young woman's boyfriend, Jesse Wolff, and other acquaintances of Spierer's.

Spierer, of Greenburgh, N.Y., is a fashion merchandising major who had just finished her sophomore year at the university.

Spierer was reportedly at Rosenbaum’s apartment twice on the morning of June 3. Rosenbaum told Bloomington police in a statement June 4 that he last saw the young woman walking eastbound at 4:30 a.m. after trying to convince her to sleep at his apartment, Fox 59 reports.

Sources told the station that 15 minutes earlier Spierer used Rosenbaum’s phone to call another friend, David Rohn, who did not answer.

"She was intoxicated," Rohn reportedly said.

The station reports that Rohn had been with Spierer at Rosenbaum’s apartment earlier in the morning. "I was with her that night actually. We were hanging out with our friends right here and I believe she went to (Kilroy’s) and I went to Smallwood and that’s the last I saw her," he said.

Spierer's parents have repeatedly pleaded for her friends and acquaintances to come forward with information.

"Perhaps it was a terrible accident that happened, and we can deal with that," Spierer's mother, Charlene Spierer, said at a press conference last week. "What we can't deal with is what we don't know."

Police have not yet named any suspects in the case.

Click for more on the disappearance of Lauren Spierer from Fox 59